EDIT: solved! read below
When I want to install MS SQL Server 2008 (R2) on my Win7 PC, I keep getting the error that I need to remove my SQL Server 2005 Express. This is, however, no longer installed.

I followed the same routine as here: SQL Server Express 2008 Install Side-by-side w/ SQL 2005 Express Fails without result.
I deleted everything linking to SQL Server 2005 and tried to install the 2008, same error …
Reinstalled 2005 and tried to update via the 2008 setup, “can’t find 2005 shared modules to update”
Deleted 2005, rebooted, ran 2008 setup, same error: need to remove 2005 Express
Reinstalled 2005, deleted shared modules, tried to install 2008, same error as above
Completely deleted 2005, rebooted, ran setup, still 2005 on the system?!
I ran the setup this time again and installed everything except the Menegement Studio.
Too bad this is the one program I definitly need to follow my classes.
I hope you guy can help me with this!
PS: I’ve got a lot of SQL programs installed, because I’ve got Visual Studio, SQLyog, … installed for my studies
SOLUTION
Found someone with the same problem: http://social.msdn.microsoft.com/Forums/en-US/sqlsetupandupgrade/thread/5fc58507-9f40-4213-acbd-32a57c8822d7/
How I solved my problem: As I have a 64bit system, I had to remove this registerfolder: HKLM\Software\Wow6432Node\Microsoft\Microsoft SQL Server\90
For 32bit systems: remove HKLM\SOFTWARE\Microsoft\Microsoft SQL Server\90
I had same issue before. It’s not about SQL Server 2005 Express, you may have some add-on installed for SQL Server 2005.
Here is my solution: